Speculative fix for xray assembler error on MachO since r349976
Speculative fix for xray assembler error on MachO since r349976

This .file directive wasn't doing anything on MachO, and now that's
diagnosed as an error.

git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@350132 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt